With increasing demand for liquid transportation fuels, decreasing reserves of ‘easy oil’ (crude petroleum oil that can be accessed and recovered easily) and increasing constraints on carbon footprints of such fuels, it is becoming increasingly important to develop routes to produce liquid transportation fuels from biomass in an efficient manner. Such liquid transportation fuels produced from biomass are sometimes also referred to as biofuels. Biomass offers a source of renewable carbon. Therefore, when using such biofuels, it may be possible to achieve more sustainable CO2 emissions over petroleum-derived fuels.
An efficient method for processing biomass into high quality liquid fuels (e.g. diesel fuel and gasoline) is described in WO 2010/117437 A1, in the name of Gas Technology Institute.
Solid feedstocks such as feedstocks containing waste plastics, feedstocks containing lignocellulose (e.g. woody biomass, agricultural residues, forestry residues, residues from the wood products and pulp & paper industries) and municipal solid waste containing lignocellulosic material, waste plastics or food waste are important feedstocks for biomass to fuel processes due to their availability on a large scale. Lignocellulose comprises a mixture of lignin, cellulose and hemicelluloses in any proportion and usually also contains ash and moisture.
Certain conventional hydroconversion catalysts used in biomass conversion, similar to those used in refining applications, are generally substantially fully sulfided, i.e. they contain near-stoichiometric quantities of sulphur (e.g. molybdenum is present substantially as MoS2 and nickel is present substantially as NiS, etc). Some disclosures teach the need to continually introduce sulfur during biomass processing to maintain hydroconversion catalysts in their sulfided state (see, for example, U.S. Pat. No. 8,278,492). By substantially fully sulfided, it is understood that more than 95% of the metal atoms on the catalyst are in fully sulfided form. In conventional hydroconversion and refining processes, sulfidation procedures followed are designed to produce such substantially fully sulfided form of the active metal component of the catalyst.
It would an advantage to provide a wide range of catalysts adaptable to a broader range of biomass feedstocks for use in the process.